This dataset contains the input and output files of density functional theory (DFT) calculations supporting the research published in the peer-reviewed article "Reductive Dechlorination of Chlorinated Ethenes at the Sulfidated Zero-Valent Iron Surface: A Mechanistic DFT Study" by M. Brumovský and D. Tunega, available at DOI 10.1021/acs.jpcc.4c00865. Please cite this article when using the dataset. This dataset includes the following data:* Structures and energies of various surface slab models, encompassing pristine and sulfidated iron surfaces (Fe(110), S-in-Fe(110), S-on-Fe(110), and S1/8ML-Fe(110)).* Structures and energies of isolated chlorinated ethene molecules (PCE, TCE, cis-DCE, and trans-DCE).* Adsorption configurations of chlorinated ethenes and their dechlorination products at the modeled surfaces.* Reaction profiles of chlorinated ethene dechlorination reactions using the CI-NEB method. * Implicit solvation calculations for surface slab models, isolated chlorinated ethene molecules, their adsorption complexes, and the adsorbed dechlorination products and transition states.* Frequency calculations of the adsorbed chlorinated ethenes and their dechlorination transition states.* High-accuracy calculations of the reaction barriers at S sites using the SCAN functional for method benchmarking.* In specific cases, data related to charge analysis and density of states calculations. Files are organized according to the respective modeled surfaces. The final geometry data can be found in the CONTCAR files, while energy data can be found in the OUTCAR files. Please note that the POTCAR files are not allowed to be made publicly accessible but are specified within the OUTCAR files. For additional details about input and output files, refer to the VASP manual. Funding: This research received support from the Austrian Science Fund (FWF) under project M 2892-N. The Vienna Scientific Cluster (Project No. 70544) is gratefully acknowledged for providing computational resources. Terms of use: These data are provided "as is", without any warranty. This dataset is provided under the Creative Commons Attribution 4.0 International license.